A bushing wear prevention milling device

Abstract

The utility model discloses a kind of anti-casing abrasion milling devices, belong to petroleum and natural gas well drilling engineering technical field, and its technical scheme main points include main body cylinder, the top and bottom of the main body cylinder are provided with drill rod joint, the outside of the main body cylinder is evenly provided with three groups of self-adapting centralizing mechanism along circumference, the application is by being provided with main body cylinder, drill rod joint, self-adapting centralizing mechanism and automatic controller, three groups of self-adapting centralizing mechanism distributed in circumference, can be according to the pressure sensor signal received by automatic controller, drive telescopic cylinder flexible adjustment, face casing diameter change, complex curvature well section, telescopic cylinder drives centralizing wheel frame, tungsten carbide centralizing wheel dynamically changes position and angle, accurately adapts different well conditions, stably restricts drill string centering, solve the problem that traditional fixed size centralizing tool adaptability is poor, cannot stably restrict drill string, effectively avoid drill string eccentric friction casing, guarantee wellbore operation safety.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas drilling engineering technology, and in particular to a milling device for preventing casing wear. Background Technology

[0002] In oil and gas drilling and well workover operations, milling and grinding processes (such as milling bridge plugs and retrieving debris) are key steps in restoring wellbore functionality. However, during milling and grinding operations, as the drill string drives the milling and grinding tool to rotate and cut, it is susceptible to eccentric swing due to factors such as uneven formation stress, fluctuations in drilling pressure, and disturbances in drilling fluid. This causes the drill string to directly rub against the inner wall of the casing, leading to casing wear problems.

[0003] While existing drilling wear protectors and other tools reduce friction by straightening the drill string, they have two prominent drawbacks: First, they lack adaptability, as most are designed with fixed dimensions, making it difficult to flexibly adjust the straightening radius according to changes in casing diameter and milling tool specifications. They are prone to failure in complex variable-diameter and curvature well sections, and cannot stably constrain the drill string to center. Second, they lack wear resistance, as straightening components are commonly made of ordinary steel or rubber. Under the high-frequency friction environment of milling operations, they will wear and deform in a short time, requiring frequent tripping out of the well for replacement. This not only increases operating costs but also delays the project due to well shutdowns. In fact, wear protector failure may even lead to major safety accidents such as casing perforation and blowouts, threatening wellbore integrity and operational safety.

[0004] To address this, a milling device for preventing sleeve wear is proposed. Utility Model Content

[0005] The purpose of this utility model is to provide a casing wear prevention milling device, which can solve the two major defects of existing drilling anti-wear tools, such as drill string straightening, which reduce friction by straightening the drill string: First, poor adaptability, as they are mostly designed with fixed dimensions, making it difficult to flexibly adjust the straightening radius according to changes in casing diameter and milling tool specifications. They are prone to failure in complex variable diameter well sections and curvature well sections, and cannot stably constrain the drill string to be centered. Second, insufficient wear resistance, as the straightening components are usually made of ordinary steel or rubber. Under the high-frequency friction environment of milling operations, they will wear and deform in a short time, requiring frequent tripping out of the well for replacement. This not only increases operating costs, but also delays the construction period due to well shutdown, and may even lead to major safety accidents such as casing perforation and blowout due to wear anti-wear device failure, threatening the integrity of the wellbore and operational safety.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a milling device for preventing sleeve wear, comprising a main cylinder, with drill rod joints provided at the top and bottom of the main cylinder, three sets of adaptive straightening mechanisms evenly arranged circumferentially on the outer side of the main cylinder, an automatic controller provided inside the main cylinder, and a wear-resistant protective sleeve fitted on the middle of the outer side of the main cylinder.

[0007] The adaptive straightening mechanism includes a telescopic cylinder embedded in the outer wall of the main body cylinder. The telescopic cylinder is electrically connected to an automatic controller. A connecting plate is fixedly connected to the telescopic end of the telescopic cylinder. A pressure sensor is embedded in the outer side of the connecting plate and is electrically connected to the automatic controller. Sliding grooves are provided at the top and bottom of the outer side of the connecting plate. A sliding rod is slidably connected inside the sliding groove. A straightening wheel frame is welded to the outer side of the sliding rod. The straightening wheel frame is located outside the pressure sensor. A tungsten carbide straightening wheel is rotatably connected inside the straightening wheel frame.

[0008] Preferably, the tungsten carbide straightening wheel has a 0.5-1mm thick tungsten carbide coating on its surface and a wheel diameter of 50-100mm.

[0009] Preferably, the wear-resistant protective sleeve is made of high-chromium cast iron with a thickness of 8-10mm, and is interference-fitted with the main body cylinder, covering 2 / 3 of the length of the main body cylinder.

[0010] Preferably, the telescopic cylinder is hydraulically driven, with a stroke range of 10-50mm, a working pressure of 3-8MPa, and is connected to the drill string hydraulic system.

[0011] Preferably, the automatic controller has a built-in pressure threshold (0.5-1MPa). When the pressure sensor detects a value exceeding the threshold, the automatic controller drives the telescopic cylinder to retract; when the value is below the threshold, it drives the telescopic cylinder to extend.

[0012] Preferably, the drill pipe joint has an NC38 or NC50 thread, and its connection strength with the main body is ≥500MPa. The connecting plate, slide rod, and centering wheel frame are all forged from alloy structural steel.

[0013] Preferably, the top and bottom sides of the centering wheel frame are both embedded with self-lubricating shaft rings, which are located on the outside of the tungsten carbide centering wheel.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1. This application sets up a main tube, drill pipe joint, adaptive centering mechanism and automatic controller. The three sets of circumferentially distributed adaptive centering mechanisms can drive the telescopic cylinder to flexibly adjust according to the pressure sensor signal received by the automatic controller. When facing changes in casing diameter and complex curvature well sections, the telescopic cylinder drives the centering wheel frame and tungsten carbide centering wheel to dynamically change the position and angle, accurately adapt to different well conditions, and stably constrain the drill string to be centered. This solves the problems of poor adaptability and inability to stably constrain the drill string of traditional fixed-size centering tools, effectively avoids drill string eccentricity and friction with casing, and ensures the safety of well operation.

[0016] 2. This application incorporates a wear-resistant protective sleeve, which is fitted onto the middle of the outer side of the main casing. In the event of an unexpected failure of the adaptive centralizing mechanism, the sleeve can directly absorb the friction with the casing, replacing the main casing in bearing the wear. Compared to traditional ordinary steel and rubber centralizing components, the wear-resistant protective sleeve can effectively slow down the wear process, reduce downtime caused by frequent replacement of centralizing components, lower operating costs, and provide a reliable layer of protection for the casing, further improving the stability and economy of milling operations. Attached Figure Description

[0017] Figure 1 This is an overall structural diagram of the anti-sleeve wear milling device of this utility model;

[0018] Figure 2 This is a structural diagram of the main body cylinder of this utility model;

[0019] Figure 3 This is a structural diagram of the adaptive straightening mechanism of this utility model;

[0020] Figure 4 This is a structural diagram of the centering wheel frame of this utility model.

[0021] In the diagram, 1. Main cylinder; 2. Drill pipe joint; 3. Adaptive straightening mechanism; 31. Telescopic cylinder; 32. Connecting plate; 33. Pressure sensor; 34. Slide groove; 35. Slide rod; 36. Straightening wheel frame; 37. Tungsten carbide straightening wheel; 4. Automatic controller; 5. Wear-resistant protective sleeve; 6. Self-lubricating shaft ring. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Please see Figure 1-4 The present invention provides the following technical solution:

[0024] A milling device for preventing sleeve wear includes a main cylinder 1, with drill pipe joints 2 at the top and bottom of the main cylinder 1, three sets of adaptive straightening mechanisms 3 evenly arranged circumferentially on the outer side of the main cylinder 1, an automatic controller 4 inside the main cylinder 1, and a wear-resistant protective sleeve 5 fitted on the middle of the outer side of the main cylinder 1.

[0025] The adaptive straightening mechanism 3 includes a telescopic cylinder 31, which is embedded in the outer wall of the main body cylinder 1. The telescopic cylinder 31 is electrically connected to the automatic controller 4. A connecting plate 32 is fixedly connected to the telescopic end of the telescopic cylinder 31. A pressure sensor 33 is embedded in the outer side of the connecting plate 32. The pressure sensor 33 is electrically connected to the automatic controller 4. Slide grooves 34 are provided at the top and bottom of the outer side of the connecting plate 32. A slide rod 35 is slidably connected inside the slide groove 34. A straightening wheel frame 36 is welded to the outer side of the slide rod 35. The straightening wheel frame 36 is located outside the pressure sensor 33. A tungsten carbide straightening wheel 37 is rotatably connected inside the straightening wheel frame 36.

[0026] In this embodiment: by setting up a main body cylinder 1, drill pipe joints 2, adaptive centering mechanisms 3, automatic controllers 4, and wear-resistant protective sleeves 5, during use, the main body cylinder 1 is connected to the upper and lower drill strings through the drill pipe joints 2 at the top and bottom, and is lowered into the casing as a whole, located in the central area of ​​the casing. When the drill string drives the main body cylinder 1 and the milling tool connected to the bottom to perform milling operations, the three sets of circumferentially distributed adaptive centering mechanisms 3 work synchronously. The telescopic cylinder 31 is initially in a retracted state, and after it is lowered into the casing along with the main body cylinder 1... The automatic controller 4 starts and drives the telescopic cylinder 31 to extend, pushing the connecting plate 32, the centering wheel frame 36, and the tungsten carbide centering wheel 37 towards the inner wall of the casing until the tungsten carbide centering wheel 37 contacts the inner wall of the casing. At this time, the pressure sensor 33 on the outside of the connecting plate 32 detects the contact pressure between the tungsten carbide centering wheel 37 and the inner wall of the casing in real time and transmits the signal to the automatic controller 4. When the drill string eccentrically swings due to factors such as formation stress and drilling pressure fluctuations, the tungsten carbide centering wheel 37 on one side contacts the inner wall of the casing. The contact pressure will increase, and the pressure sensor 33 will feed back the changed pressure signal to the automatic controller 4. The automatic controller 4 will drive the telescopic cylinder 31 on the corresponding side to retract appropriately according to the signal difference, and at the same time adjust the telescopic cylinder 31 on the other side to extend slightly. By adjusting the position of the straightening wheel frame 36 (the slide rod 35 slides synchronously with the straightening wheel frame 36 in the slide groove 34 to ensure that the wheel frame angle is suitable for the curvature of the casing inner wall), the tungsten carbide straightening wheel 37 will always be in contact with the casing inner wall with balanced pressure, pulling the drill string back to the center position of the casing and avoiding direct friction between the drill string and the casing. If the adaptive straightening mechanism 3 fails unexpectedly (such as the telescopic cylinder 31 fails), the wear-resistant protective sleeve 5 sleeved on the middle of the outer side of the main body cylinder 1 will replace the tungsten carbide straightening wheel 37 to contact the casing inner wall and bear the friction and wear, further preventing the main body cylinder 1 from directly colliding and rubbing with the casing, forming double protection. In the whole process, the rotation characteristics of the tungsten carbide straightening wheel 37 will convert sliding friction into rolling friction. Combined with the protective effect of the wear-resistant protective sleeve 5, the risk of casing wear will be minimized.

[0027] Specifically, such as Figure 4 As shown, the tungsten carbide straightening wheel 37 has a 0.5-1mm thick tungsten carbide coating on its surface and a wheel diameter of 50-100mm.

[0028] Specifically, such as Figure 1 , Figure 2 As shown, the wear-resistant protective sleeve 5 is made of high-chromium cast iron with a thickness of 8-10mm. It is interference-fitted with the main body cylinder 1 and covers 2 / 3 of the length of the main body cylinder 1.

[0029] Specifically, such as Figure 3 As shown, the telescopic cylinder 31 is hydraulically driven, with a stroke range of 10-50mm and a working pressure of 3-8MPa, and is connected to the drill string hydraulic system.

[0030] In this embodiment: the 0.5-1mm thick tungsten carbide coating covering the wheel surface of the tungsten carbide centralizing wheel 37, combined with a wheel diameter design of 50-100mm, not only utilizes the high hardness of tungsten carbide to improve the wear resistance of the wheel surface, but also reduces the contact pressure per unit area through the larger wheel diameter, thereby reducing wear on the inner wall of the casing. The wear-resistant protective sleeve 5 made of high-chromium cast iron is 8-10mm thick and is interference-fitted with the main cylinder 1, covering 12 / 3 of the length of the main cylinder 1. It can resist friction with high strength when the adaptive mechanism fails, and the interference fit ensures that it will not fall off due to vibration. The hydraulically driven telescopic cylinder 31, with a stroke of 10-50mm and a working pressure of 3-8MPa, can flexibly adapt to different casing gaps. The connection with the drill string hydraulic system ensures a stable power supply and achieves precise control of the position of the tungsten carbide centralizing wheel 37.

[0031] Specifically, such as Figure 2 As shown, the automatic controller 4 has a built-in pressure threshold (0.5-1MPa). When the pressure sensor 33 detects a value exceeding the threshold, the automatic controller 4 drives the telescopic cylinder 31 to contract; when the value is below the threshold, it drives the telescopic cylinder 31 to extend.

[0032] Specifically, such as Figure 1 , Figure 2 As shown, the thread of the drill pipe joint 2 is NC38 or NC50, and the connection strength with the main body cylinder 1 is ≥500MPa. The connecting plate 32, the slide rod 35 and the straightening wheel frame 36 are all forged from alloy structural steel.

[0033] In this embodiment: the automatic controller 4 has a built-in pressure threshold of 0.5-1MPa. When the pressure sensor 33 detects a value exceeding the limit, it drives the telescopic cylinder 31 to retract. When the value is below the threshold, it controls the cylinder to extend, forming a closed-loop regulation to ensure that the tungsten carbide straightening wheel 37 always maintains a safe contact pressure with the inner wall of the casing, avoiding excessive pressure that could wear out the casing or insufficient pressure that could cause the straightening effect to be lost. The drill pipe joint 2 of NC38 / NC50 specification is fixed to the main body cylinder 1 with a connection strength of ≥500MPa, ensuring the stable transmission of drill string torque and drilling pressure. The connecting plate 32, slide bar 35 and straightening wheel frame 36, which are forged from alloy structural steel, improve the overall impact resistance and deformation resistance of the adaptive straightening mechanism 3, adapting to the high-frequency vibration environment of milling operations.

[0034] Specifically, such as Figure 4 As shown, self-lubricating shaft rings 6 are embedded in the top and bottom sides of the centering wheel frame 36, and the self-lubricating shaft rings 6 are located on the outside of the tungsten carbide centering wheel 37.

[0035] In this embodiment: by setting the self-lubricating shaft ring 6, the frictional resistance of the tungsten carbide straightening wheel 37 during rotation can be reduced, avoiding jamming of the tungsten carbide straightening wheel 37 from affecting the straightening effect. At the same time, the wear rate of the wheel frame and wheel body is reduced, the service life of the tungsten carbide straightening wheel 37 is extended, and its flexible rotation characteristics are ensured during long-term rolling contact.

[0036] Working principle: In the use of the anti-casing wear milling device, firstly, the main body cylinder 1 is securely connected to the upper and lower drill strings through the drill pipe joints 2, which are made of NC38 or NC50 threads with a connection strength ≥500MPa, at the top and bottom. The whole unit is lowered into the casing and located in the central area, moving synchronously with the drill string. During operation, the automatic controller 4 inside the main body cylinder 1 is activated, driving the three sets of circumferentially distributed adaptive centering mechanisms 3 to work. The hydraulically driven telescopic cylinder 31 (stroke 10-50mm, working pressure 3-8MPa) interacts with the drill string fluid. The pressure system is connected and initially in a contracted state. As the main casing 1 is lowered into the casing, it extends, pushing the connecting plate 32, the centering wheel frame 36, and the tungsten carbide centering wheel 37 towards the inner wall of the casing until the wheel contacts the inner wall. At this point, the pressure sensor 33 on the outside of the connecting plate 32 detects the contact pressure in real time and transmits the signal to the automatic controller 4. The automatic controller 4 has a built-in pressure threshold of 0.5-1 MPa, forming a closed-loop regulation: when the pressure on a certain side exceeds the threshold (the drill string deviates to that side), the corresponding telescopic cylinder 31 is driven to contract; when it is below the threshold, it is controlled... Extending outwards, the connecting plate 32, slide rod 35, and straightening wheel frame 36 are forged from alloy structural steel to ensure structural stability during adjustment. The slide rod 35 slides synchronously within the slide groove 34, ensuring that the angle of the straightening wheel frame 36 always adapts to the curvature of the inner wall of the sleeve, guaranteeing that the tungsten carbide straightening wheel 37 fits the sleeve with balanced pressure. The tungsten carbide straightening wheel 37, with a wheel surface covered with a 0.5-1mm thick tungsten carbide coating and a wheel diameter of 50-100mm, converts sliding friction into rolling friction during rotation. This utilizes the high-hardness coating to improve wear resistance and reduces wear through a reasonable wheel diameter. The pressure on the casing is further reduced by the self-lubricating shaft ring 6 inside the centering wheel frame 36, which prevents jamming and extends the wheel life. If the adaptive centering mechanism 3 fails unexpectedly, the wear-resistant protective sleeve 5, made of high-chromium cast iron with a thickness of 8-10mm, which is interference-fitted with the main body cylinder 1 and covers 2 / 3 of its length, will directly bear the friction with the casing, forming double protection. The whole process achieves a dynamic balance between drill string centering constraint and casing wear protection through the synergy of mechanical structure and intelligent control, ensuring that the milling operation is stable and efficient.

[0037] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A milling device for preventing sleeve wear, comprising a main body cylinder (1), characterized in that: The top and bottom of the main body tube (1) are provided with drill pipe joints (2), and three sets of adaptive straightening mechanisms (3) are evenly arranged on the outer side of the main body tube (1) along the circumference. An automatic controller (4) is provided inside the main body tube (1), and a wear-resistant protective sleeve (5) is fitted on the middle part of the outer side of the main body tube (1). The adaptive straightening mechanism (3) includes a telescopic cylinder (31), which is embedded in the outer wall of the main body cylinder (1). The telescopic cylinder (31) is electrically connected to the automatic controller (4). A connecting plate (32) is fixedly connected to the telescopic end of the telescopic cylinder (31). A pressure sensor (33) is embedded in the outer side of the connecting plate (32). The pressure sensor (33) is electrically connected to the automatic controller (4). Slide grooves (34) are provided at the top and bottom of the outer side of the connecting plate (32). A slide rod (35) is slidably connected inside the slide groove (34). A straightening wheel frame (36) is welded to the outer side of the slide rod (35). The straightening wheel frame (36) is located outside the pressure sensor (33). A tungsten carbide straightening wheel (37) is rotatably connected inside the straightening wheel frame (36).

2. The anti-sleeve wear milling device according to claim 1, characterized in that: The tungsten carbide centering wheel (37) has a 0.5-1mm thick tungsten carbide coating on its surface and a wheel diameter of 50-100mm.

3. The anti-sleeve wear milling device according to claim 1, characterized in that: The wear-resistant protective sleeve (5) is made of high-chromium cast iron with a thickness of 8-10mm. It is interference-fitted with the main body cylinder (1) and covers 2 / 3 of the length of the main body cylinder (1).

4. The anti-sleeve wear milling device according to claim 1, characterized in that: The telescopic cylinder (31) is hydraulically driven, with a stroke range of 10-50mm and a working pressure of 3-8MPa, and is connected to the drill string hydraulic system.

5. The anti-sleeve wear milling device according to claim 1, characterized in that: The automatic controller (4) has a built-in pressure threshold (0.5-1MPa). When the pressure sensor (33) detects a value exceeding the threshold, the automatic controller (4) drives the telescopic cylinder (31) to contract. When the value is below the threshold, the telescopic cylinder (31) is driven to extend.

6. The anti-sleeve wear milling device according to claim 1, characterized in that: The drill pipe joint (2) has a thread of NC38 or NC50 and a connection strength with the main body cylinder (1) of ≥500MPa. The connecting plate (32), slide rod (35) and centering wheel frame (36) are all forged from alloy structural steel.

7. The anti-sleeve wear milling device according to claim 1, characterized in that: The top and bottom sides of the centering wheel frame (36) are both inlaid with self-lubricating shaft rings (6), which are located on the outside of the tungsten carbide centering wheel (37).

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